Abstract: A cloning vector comprises a replication system derived from the pTAR plasmid and capable of stable maintenance in Agrobacterium tumefaciens. By combining the pTAR replication system with a second replication system from a host other than A. tumefaciens, shuttle vectors are obtained which allow manipulation in more than one host. The cloning vectors will usually include selectable markers having restriction enzyme sites which allow identification of recombinant molecules by insertional inactivation. By providing at least a fragment of the T-DNA region from the Ti plasmid, the subject vectors can be used to clone desired DNA fragments and transfer these fragments to the genome of a higher plant.The strain E. coli HB101/puc0400 was deposited on June 7, 1983 at the A.T.C.C. for patent purposes and granted accession no. 39377.